Content area
Full Text
Introduction
Aluminum Metal injection Molding (MIM) was introduced more than a decade ago but never achieved significant growth even though several research studies and patents published the advantages of MIM aluminum parts along with their test results. Intricate parts with light weight, higher thermal and electrical conductivities make aluminum MIM a viable option for several small parts in many industries including electronic industry. The study summarizes the path of aluminum MIM over the years and the recent powder and feedstock development in Aluminum MIM. The paper discuss the newly designed pre-alloyed aluminum powder grades that gives excellent mechanical properties when combined with a newly developed binder for Aluminum MIM. These aluminum alloyed powders were formulated to aid the sintering process but process conditions are optimized for each grades. The paper discuss the 6061 type alloy as a case study and share the processing conditions and mechanical properties.
The paper published by Z.Y. Liu, D. Kent, G.B. Schaffer in 2009 reported an aluminum nitride (AlN) reinforced 6061 alloyed powder composition for metal injection molding and the processing of the parts in a sintering furnace surrounded by magnesium blocks to capture the oxygen [1]. Aluminum based powder grades are not new to the Powder Metallurgy (PM) industry and millions of automobile parts have been produced by the part producers in USA for more than two decades. Just like the difficulties aluminum PM technology has experienced in its infant stage aluminum MIM is also going through the difficulties of optimizing the raw materials and processing steps to make it an attractive material of choice and technology.
Metal injection molding (MIM) is a proven technology with major processing steps of starting with a fine metal powder tailored for MIM and mixing it with a binder to create the feedstock which is then injection molded to a part with three dimensional shape, then removing the binder by different techniques and producing the finished part to the required geometry by sintering process. During the last three decades many materials such as stainless steel grades have gained popularity and these metal powder grades were optimized for MIM process and MPIF standards were established along with the processing steps. This has not happened for aluminum but a new aluminum MIM feedstock is...